Lamp starting device



Oct. 11, 1932. c, SPAETH 1,881,975 1 I LAMP STARTING DEVICE Filed Jan. 18. 19:50

cum-me s 5% 1H INVENTOR ATTORNEY Patented Oct. 11, 1932' UNITED STATES PATENT omen CHARLES SPAE 'IH OF FLUSEENG, YORK, ABSIGNOB TO NE-ABGA CORPORATION,

OF NEW YORK, IN. -A- CORPORATION OI NEW YORK Application filed January 18, 1830.-- 8eria1 No. 421,681.

This invention relates to starting devices for mercury arc lamps and similar apparatus. It is an object of my invention to provlde a starting. arrangement for mercury arc lamps or similar electrical discharge devices, that 1s so arranged as to be 0 erative for but a relatively short period 0 time after energizing current is supplied to the device in whlch the starting arrangement is associated. In the roduction of talking moving pictures it is important to have, as nearly as possible, a complete absence of all unnecessary noises and electrical disturbances. Mercury arc lamps equipped with starting devices of the type known heretofore, are unsuitable for use in the production of talking pictures because when one of the lamps becomes exting'uished the starting device thereof immedlately starts to function so as to reignite the.

lamp,therebyproducingaclickingnoise. The

noise produced by the ordinary starting 'device is suflicient to cause a serious disturbance, which will bemade part of the sound record. Likewise,when the startingdeviceservestocreate a momentary high potential starting current, the starting current causes a disturbance in the recording of the sound, if an electrical process is being used. This recording is usually carried out by electrical recording apparatus including a high power amplifier which serves to amplify the sound currents picked up through microphones. These, amplifiers are suificiently powerful to pick up the disturbing electrical waves as well, thereby impressing on the recording medium an undesired noise. I

In accordance with my invention I provide time controlled means which, a shortinterval after application of an operating potential to the lamp renders inactive the starting mechanism so that if the lamp becomes extinguished thereafter the starting device will be unable to function. The lamp will therefore remain unlit until it is manually restored to operation at an opportune moment. I accomplish this result by providing a thermostatic switch, the operating element of which gradually becomes heated after the closing of the main line switch of 0 the lamp so that after a short interval of .time the contacts of the thermostatic switch are opened. These contacts are connected in the current energizing line of the automatic starting device so that said device is ren-' dered inoperative for the opening of the contacts just mentioned.

The objects and advantagesof my inventlon and the manner of attaining them will be made clear in the following description and accompan ing drawing. Q

In the rawing, reference numeral 1 indicates an electrical discharge illuminating tube which may be either of the type disclosed in my copending application Serial No. 343,873, filed Marc 2, 1929 or ofthe ordlnary mercury arc type. As shown in the drawmg the envelope is provided with an alkaline metal cathode 2, an anode 3, and an auxiliary electrode 4 of mercury. Current from a power source is supplied to the device through the main conductors 5 and 6 which may be joined to a direct current line. Serially connected in one of the main conductors is a controlswitch 7 which serves to open or closethe energizing circuit of the tube 1. When this switch is closed'currentflows from the conductor 5 through the switch, the

controlresistances 8 and 9 through the tube 1 and back to the supply line over the con- ,ductor 6. With devices of the type mentioned above, starting current is needed, the potential of which is higher than is necessary for the normal operation of the device. This high potential issupplied by means comprising an inductance coil 10, insertedin series with one of the supply conductors, and provided with a make and break control switch 11 of the mercury or any other suitable type. The entire starting mechanism comprising the inductance coil 10 and'switch 11 may be of any well known type and hence need not be described more in detail. When the main line switch 7 is closed the current passes by means of a wire 12 through a thermostatic switch 13, current limiting resistance 14,

' switch 11, coil 10 back of the other side of the magnetized, attracting the pivotally mounted armature 16 and causing the contact of switch '11jto opened. The supply circuit of the coil 10 nowbeing broken a high inductive potential is applied across the tube 1 thereby ionizingthe gas therein and initiating operation," f the tube 1 does not start operating on ,the' first break of the switch 11 the armature 16 is immediately tilted back to its original position by any suitable means such as spring 17 ,whereby the contacts of switch 11 are again closed and the operation repeated untilthe discharge through the lamp ispermanently established. During the time the starting mechanism is operating a current passes from the wire 12 through the. heat-' ing resistance 18, back to the other side of the line. This heating element 18 serves to heat the thermostatic element of the switch 13 thereby causingthe contacts thereof to open after a shortinterval of time. This interval is made longvenoughjby the proper selection of the heating-element 18 to allow for the starting of the tube 1 by the mechanism already described, The periodis made sufnism to operate several times if necessary in order to create a self-sustaining discharge through the tube. After the current has been on for a slightlylonger interval of time, the

contacts of the thermostatic switch 13 are opened and maintained open by the heating sired operation of the starting mechanism ficiently long .to enable the starting mechaafter having been put in operation, the startchar e' illuminating tube, an automatic in;

ductive starting device therefor, an 0 erating circuit, an energizing circuit for sai start ing device, a pair of swltch contacts in series with said energizing circuit and thermostatic means for opening said contacts a short interval of time after the application of an energizing potential to said system.

In testimony whereof, I have signed my name to this specification, this 16th day of January, 1930. 1

CHARLES 'SPAETH.

can takeplace, and absence'of disturbing noises and electrical waves is insured. The functlon of condenser 19 1s to prevent arclngat the contacts 11 and thereby increase the potential created by the'coil 10. While but'a single lamp is-show'n in the drawings several 7 lamps might be controlled by a single thermostatic switch 13. In this caseeach of the nected as to have its operating' circuit broken by switch 13. v 7

It '11 be obvious to those skilled in the art that the invention is capable of a wide variety that the present disclosure is intended merely several starting mechanisms would be so con-' of modifications and adaptions and to illustrate its nature without limiting its.

of ener- 

